title: Cellular organization of cortical barrel columns is whisker-specific.
abstract: The cellular organization of the cortex is of fundamental importance for elucidating the structural principles that underlie its functions. It has been suggested that reconstructing the structure and synaptic wiring of the elementary functional building block of mammalian cortices, the cortical column, might suffice to reverse engineer and simulate the functions of entire cortices. In the vibrissal area of rodent somatosensory cortex, whisker-related "barrel" columns have been referred to as potential cytoarchitectonic equivalents of functional cortical columns. Here, we investigated the structural stereotypy of cortical barrel columns by measuring the 3D neuronal composition of the entire vibrissal area in rat somatosensory cortex and thalamus. We found that the number of neurons per cortical barrel column and thalamic "barreloid" varied substantially within individual animals, increasing by ∼2.5-fold from dorsal to ventral whiskers. As a result, the ratio between whisker-specific thalamic and cortical neurons was remarkably constant. Thus, we hypothesize that the cellular architecture of sensory cortices reflects the degree of similarity in sensory input and not columnar and/or cortical uniformity principles.
authors.affiliation: Digital Neuroanatomy, Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458.
authors.forename: Hanno S
authors.initials: HS
authors.lastname: Meyer
authors.forename: Robert
authors.initials: R
authors.lastname: Egger
authors.forename: Jason M
authors.initials: JM
authors.lastname: Guest
authors.forename: Rita
authors.initials: R
authors.lastname: Foerster
authors.forename: Stefan
authors.initials: S
authors.lastname: Reissl
authors.forename: Marcel
authors.initials: M
authors.lastname: Oberlaender
mesh_terms: D000344:Afferent Pathways / Q000166:cytology; D000818:Animals; D002452:Cell Count; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal; D008959:Models, Neurological; D051381:Rats; D017208:Rats, Wistar; D013003:Somatosensory Cortex / Q000166:cytology*; D014738:Vibrissae / Q000294:innervation*
keywords: GAD67; NeuN; VPM; barrel cortex; soma counts